High-frequency generator.



R. GOLDSGHMIDT.

HIGH FREQUENCY GENERATOR.

APPLICATION FILED MAYQ, 1911.

Patented July 21, 1914,

8 woe W607,

RUDOLF eonnsonminr, or DARMSTA'DT, GERMANY.

nremrnn'o'unncy' GENERATOR.

Specification Letters Patent.

Patented July 21; 1914.

Application filed May 9, 1911. Serial NO. 625,988.

To'all 'wh-Om-it-may concern:

Be it known that I, RUDOLF GOLDBCHMIDT, asubjec't of theGrrand Duke of Hesse, and residing-at Darmstadt, in theGrand Duchy of Hesse, Germany, have invented a-new and Improved High-Frequency Generator, of which the following is a specification.

This invention relates to a novel generator for producing electric currents of high freqtlency: whichpossesses the characteristic feature thatits stator and rotor are provided withgmonophase windings in lieu of the' polyphase' windings hitherto generally employed.

The following comparison between machines" provided with polyph'ase windings and-machineshaving 'monophase windings will clearly demonstrate the'advantages of the latter. It is an acknowledged principle in practicewhat an excessive high speed of the rotor should be avoided, but such a high speed can only be obviated by correspondingl'y. increasing the number of poles of the machine. As thisnu-mber however increases with the number of phases generated and as the number of poles in-turn determines the diameter of-the generator, it is obvious that polyphase generators will assume object-ionably large dimensions under the conditions cited. Applicant overcomes this objection and generates monophase current by providing the stator-as well as the rotor of the machine with monophase windings, so that a corresponding. reduction of the'number of poles is obtained without reducing the frequency of'the generated monophase' current when compared with the above described generation of polyphase current, and withouthaving'in any wise to resort to the above mentioned undesirable high speed of the rotor. A single frequency current, however, can only be obtained, in the member inductively acted upon, when the inductive member produces a perfect rotary field; accordingly. it has hitherto been necessary to use windings carrying at least two phases on the inductive member, because a single phase winding per se will not set up a rotary field. To'nevertheless obtain the above men'- tioned-advantages of a monophase winding, my invention is. based on the fact that a monophase field may be consideredasmade upof two fields rotating synchronously in opposite directions and each having half the maximum value of the monophase field..,55

These two rotating fields will induce in the rotor windings two frequencies, one of which is nullified according to my invention by making use of'theprinciple of resonance, so that in this way one of the frequencies can be suppressed while the other is simultaneously developed for use in a circuit of utilization.

In the accompanying drawing: Figure-lis a diagram of a high-frequency generator embodying my inventi0n; Fig. 2 a diagram of a modification thereof, andFig. 3 a'diagram of a further modification. T

Referring-to Fig. '1, S indicates'a monophase stator winding, the terminals a, a -of which are connected to a suitable supply of alternating current having the frequency V Within the two rotary fields of which the single phase pulsating field of the stator may be considered to be the equivalent, is rotated the monophase rotor winding R with the alternating speed W the rotor'being driven by a belt D or otherwise. In this way, the effect of two frequencies W and W will arise in the rotor winding according to the following formulas:

The rotor winding is connected to a condenser C which is tuned to the self induction of such winding for the frequency not desired, while the condenser C,- and theinductance L interpolated between the points I) and Z), which are respectively connected to the rotor winding and condenser C, are tuned to the same frequency. The antenna F is by wire d connected to point 6, while point I), is through wire 6 grounded as at E. In this way, the circuit which is composed of the rotor winding, condenser C, inductance L and condenser C will serve for the passage of the frequency not desired, while the frequency desired is conducted from the points I) and b, to the antenna and ground respectively. In order to eliminate disturbances in the circuit of utilization which may have their origin in the formation of harmonic oscillations and other causes, this circuit is preferably provided with means for tuning it to the frequency desired,; for

which purpose a tuning coil L and a condenser C are respectively inserted between the point I; and the antenna and between the pointb and the ground.

My invention is of particular importance Whenever it is desired to change the frequency furnished by a high frequency generator without changing the rotary speed thereof. This is effected by making use of a supplementary transformer constructed in accordance with this invention, the rotary speed of which may be changed more easily and quicker than that of the generator. If

, ner with the alternating speed W The denser C and an inductance L winding of rotor R is connected to a con- If a current '5, of the frequency W is sent through the winding of stator 8,, there is produced in the winding of rotor R a current i of the frequency it being assumed that the frequency W YV be nullified. The current 2', thus produced reacts on the stator S and here induces a current i having a frequency it being also assumed that the frequency lV '-W be eliminated. In this Way, a multistage transformation of frequencies may be readily obtained, it being obvious that the steps for raising the frequency may be increased by arranging a second rotor in the field of stator S and so on. On the other hand, if it is desired to attain the increase of the frequency in one stage only, continuous current may be sent through the winding of stator S so that the winding of rotor R is employed as a generator-armature as well as a primary alternating current winding. The circuit of utilization may be established in various manners, the drawing showing one end of the winding of stator S connected at 6 to a condenser C and an inductance L while the latter is connected to the other end of said stator winding. The antenna F and a tuning coil L, are connected to the point b while the point 6 is connected to condenser C and round E. With the connections described, the circuit S C L is tuned to the frequency not desired, while the antenna together with the parts L and C are tuned to the desired frequency.

For thepurpose of the invention as defined in the appended claims,a plurality of stators and a single rotor are to be considered equivalents of a plurality of rotors and asingle stator.

The invention may also be adapted for the generation of multiphase current as is for instance, used for certain telegra hic purposes, such an arrangement being i lustrated in Fig. 3. Here a plurality of stators S,, S are mounted side by side and the corresponding rotors R R are mounted on a common shaft G, the number of stator and rotor pairs corresponding .to the phase number,

while these parts are 'locall displaced in accordance with time phase differences. The windings of rotors R R are connected to condensers C C and inductances L,, L respectively to establish the desired resonant rotor circuits. With the wiring shown iii-Fig. 3, it is assumed that a air of an-- tennae F and F" be supplied with currents of different phases. These antennae are respectively connected over tuning coils L" and L to the points 1),, 6, while the points b I), are grounded as at E.

I claim:

1. A high frequency generator comprisin rotor and stator parts, each provided wit single phase'windings, a condenser, and connections between the condenser and the windings of the rotor adapted to establish a resonant rotor circuit.

2. A high frequency generator com rising a stator having slngle phase win ings adapted to receive alternatin current, a rotor having single phase windings, a condenser, and connections between the condenser and the windings of the rotor constituting a resonant circuit for nullifying one of the frequencies generated in the rotor circuit.

3. A high frequency generator compri a plurality of stators, each being provid with single phase windings, a rotor movable in the fields of said stator windings and also provided with single phase windings and tuning agencies connected to one set of said single phase windings.

4. A high frequency transformer comprising afirst stator havlng single phase windings and adapted to receive an exciting current, 'asecond stator having single phase windings, a rotor arranged opposite both of said stators and having single phase windings, a condenser, and connections between the condenser and the windings of the second stator and adapted to establish a resonant second stator circuit.

5. A high frequency transformer comprising a first stator having single phase windings and adapted to receive an exciting current, a second stator having single phase windings, a rotor arranged opposite both of said stators and having single phase windings, a first condenser, connections be- In testimony whereof I aflix my signature in presence of two witnesses.

PROF. DR. RUDOLF GOLDSCHMIDT.

\Vitnesses HENRY HASPER, WOLDEMAR HAUPT. 

